PHILADELPHIA -- The bugging of Mayor John F. Street's office during a campaign marked by accusations of race-baiting has heightened long-standing tensions between blacks and the FBI -- concerns that date to the 1960s civil rights movement.

Many in Philadelphia's black community say the mayor would not be under such scrutiny if he was white, and Street himself suggested this week that "racial biases" could have something to do with the FBI investigation.

The FBI has refused to provide details about the hidden listening devices found Tuesday. Street said federal prosecutors have assured him he is not a target of the investigation.

"If he's not the target of the investigation, why bug his office?" said Michael Coard, a black Philadelphia lawyer and activist. "He's the mayor, he's a black man, he's a lawyer."

Black leaders long have alleged that there is a pattern of racial bias by the FBI, citing J. Edgar Hoover's authorization of wiretaps on Martin Luther King Jr. because he thought the civil rights leader was a communist. They also point to investigations of Malcolm X, former Washington, D.C., Mayor Marion Barry and other prominent black figures.

"There's been, and the FBI has admitted it at times, unfair investigation and surveillance of African-Americans," said Rep. Chaka Fattah, D-Pa., who is black. "There's less restraint on the leash."

Callers to Coard's weekly talk show, aired on WHAT-AM, which calls itself "The Voice of the African-American Community," echoed his concerns this week, with dozens of calls in support of Street. "They all suspect that it's racially and politically motivated," Coard said.

A Justice Department spokeswoman did not return a telephone call Friday.

Street addressed the issue during a debate with Republican challenger Sam Katz on Thursday. "In the true spirit of candor, there are some people, particularly in the African-American community, that believe this is too much of a coincidence to be a coincidence," Street said.

Unrelated to campaign

Katz and the FBI have said his campaign had nothing to do with the listening devices.

Supporters of both Street and Katz, who is white, have accused each other of race-baiting. In August, someone tossed what was believed to have been an unlit firebomb through the window of a Katz campaign office. An aide to Street and a former city employee were charged with making threats after getting into a confrontation the same day.

A group of clergy members and other civic leaders, under the name Philadelphians for Justice and Fair Play, scheduled a prayer vigil for Street this morning, in part because of racial concerns.

"There's a significant strain. It's impossible to measure it or quantify it," said J. Whyatt Mondesire, president of the Philadelphia chapter of the National Association for the Advancement of Colored People, who planned to attend the vigil.

He said the bugging is "reminiscent" of the investigations of other prominent black leaders and black groups, including the Black Panthers and the Student Nonviolent Coordinating Committee, the 1960s civil rights group. Malcolm X and others also frequently expressed concerns that they were being monitored by the FBI and other agencies.

In 1990, Washington, D.C., Mayor Marion Barry was indicted on perjury and cocaine possession charges stemming from an FBI sting operation that caught him smoking crack cocaine in a downtown Washington hotel. He was convicted on misdemeanor possession charge and served six months in jail.

"When you start talking about an FBI-initiated action, and it involves a black elected official, there's automatically suspicion as to what's going on," said state Rep. James Roebuck, a black Democrat from Philadelphia.